In a case of a NAND flash memory device which includes a flash translation layer (FTL), the NAND flash memory device may need to ensure that write data output from a host are completely programmed in the NAND flash memory device.
When programming data in the NAND flash memory device, and when a block of a memory cell array to be programmed is a bad block, a program failure occurs. The NAND flash memory device needs to perform a garbage collection on the bad block so as to process the program failure, which results in the program time for program completion being prolonged. Accordingly, while the garbage collection is performed, the NAND flash memory device is in a long busy state.
Regarding data read operations, as manufacturing NAND memory cells included in a NAND flash memory device is refined, an uncorrectable error is increased in data output from the NAND memory cells, and a host uses various methods to correct the error. Accordingly, read latency of the host may be increased.
A method of increasing a data processing capability of a data storage device, e.g., a data server, includes a scale up and a scale out. The scale up improves the data processing capability of the data server by increasing a capacity of the data server itself, and is also referred to as vertical scaling. The scale out improves a data processing capability of a system including the data server by increasing the number of connected data servers, and is also referred to as horizontal scaling.
In a data storage device having a scale up structure, when the number of non-volatile memory devices included in the data storage device is increased, loading capacitance of an interface embodied between a controller controlling the non-volatile memory devices and the non-volatile memory devices is increased. Accordingly, a data processing speed of the data storage device may be decreased.